1. Field of the Invention
The present invention relates to a terminal for electric connector for communication and, more particularly, to such a terminal that easily positively be positioned in the connector housing for signal transmission without producing much impedance.
2. Description of the Related Art
Communication apparatus are important implement for communication among people at distance. Advanced communication apparatus commonly have a small size with high transmission power. For a compact communication apparatus, the component parts and terminals must be made relatively smaller. FIG. 1 shows a terminal for electric connector for communication apparatus according to the prior art. According to this design, the terminal, referenced by 100, is stamped from a metal sheet member, comprising a protruding contact portion 102 disposed at one end, a mounting plate portion 10 disposed at the other end, a spring coil portion 101 connected between the protruding contact portion 102 and the mounting plate portion 10, a bonding tip 10b extended from the bottom side of the mounting plate portion 10 for soldering to a circuit board, and two hooks 10a protruding from two opposite lateral sides of the mounting plate portion 10. During installation, the terminal 100 is inserted into the receiving chamber 21 of an electrically insulative housing 20 for electric connector to force the hooks 10a into engagement with the inside wall of the housing 20 (see FIG. 1A). When installed, the protruding contact portion 102 extends out of the front opening of the housing 20 for contact. This design of terminal 100 for electric connector is still not satisfactory in function. Due to weak structural strength, the terminal 100 tends to be permanently deformed or damaged during installation of the electric connector (see FIG. 1B).
FIG. 2 shows another structure of terminal for electric connector according to the prior art. This design of terminal is similar to that shown in FIG. 1 with the exception of the two additional parallel side guide strips 103 that are bilaterally extended from the top side of the mounting plate portion 10 in direction reversed to the bonding tip 10b and spaced from the spring coil portion 101 at two sides. This structure of terminal is still not satisfactory in function because the protruding contact portion 102 tends to be biased, affecting signal transmission quality. Further, in order to reduce impedance produced during signal transmission, beryllium copper is used for making the terminal. However, a terminal of beryllium copper is relatively expensive.
In order to eliminate the aforesaid drawbacks, the inventor invented an improved structure of terminal. This design of terminal 300 comprises a protruding contact portion 35 disposed at one end, a mounting plate portion 30 disposed at the other end, two spring coil portions 34 symmetrically bilaterally connected between the protruding contact portion 35 and the mounting plate portion 30, a bonding tip 31 extended from the bottom side of the mounting plate portion 30 for soldering to a circuit board, two hooks 33 protruding from two opposite lateral sides of the mounting plate portion 30, and two springy retaining strips 32 protruded from the mounting plate portion 30 and spaced between the hooks 33. As shown in FIG. 4, the terminal 300 is inserted into the receiving chamber 21 of an electrically insulative housing 20 for electric connector to force the springy retaining strips 32 and the hooks 33 into engagement with the inside wall of the housing 20. When installed, the protruding contact portion 35 extends out of the front side of the housing 20, and the two spring coil portions 34 keep the protruding contact portion 35 in balance. Therefore, the use of the electric connector does not cause the protruding contact portion 35 to bias. Further, the terminal 300 is directly stamped from a phosphor bronze sheet member for the advantages of low impedance and low cost.